Inorganic phosphorous is a naturally occurring element in allplants and animals, with concentrations increasing progressively upthe food chain (fruit < vegetables < cereals < nuts | Region I: x1;n1 = 12 |
| 540 | 810 | 790 | 790 | 340 | 800 |
| 890 | 860 | 820 | 640 | 970 | 720 |
| Region II: x2;n2 = 16 |
| 750 | 870 | 700 | 810 | 965 | 350 | 895 | 850 |
| 635 | 955 | 710 | 890 | 520 | 650 | 280 | 993 |
(a) Use a calculator with mean and standard deviation keys tocalculate x1, s1,x2, and s2. (Round youranswers to one decimal place.)
| x1 | =Â Â ppm |
| s1 | =Â Â ppm |
| x2 | =Â Â ppm |
| s2 | =Â Â ppm |
(b) Let μ1 be the population mean forx1 and let μ2 be thepopulation mean for x2. Find an 80% confidenceinterval for μ1 − μ2.(Round your answers to one decimal place.)
| lower limit     | ppm |
| upper limit | ppm |
